C8 aromatics processing

Claim 1

IN THE PREPARATION OF STYRENE FROM A MIXTURE OF ETHYLBENZENE, XYLENE ISOMERS AND NON-AROMATIC HYDROCARBON COMPONENTS, THE STEPS OF PREFRACTIONATING THE MIXTURE TO FORM C8 AROMATICS CONTAINING A LARGE QUANTITY FROM ABOUT 1% TO ABOUT 5% OF NON-AROMATIC COMPONENTS BOILING IN ABOUT THE C8 AROMATIC HYDROCARBON BOILING RANGE, SUPERDISTILLING THE SAID HYDROCARBON MIXTURE IN A DISTILLATION COLUMN OF AT LEAST 150 DISTILLATION STAGES AND AT A REFLUX RATIO EXCEEDING 40:1 TO SEPARATE THE XYLENES AND PASSING THE MIXTURE OF PURE ETHYL BENZENE AND NONAROMATIC HYDROCARBON MIXTURE TO A DEHYDROGENATION REACTOR TO CONVERT THE ETHYL BENZENE TO STYRENE IN THE PRESENCE OF SAID NON-AROMATIC HYDROCARBON, SEPARATING SUBSTANTIALLY PURE STYRENE FROM THE CRUDE DEHYDROGENATION REACTION MIXTURE BY DISTILLATION AND RECYCLING AT LEAST A PORTION OF SAID UNREACTED MIXTURE OF ETHYL BENZENE AND NON-AROMATIC HYDROCARBON TO SAID PREFRACTIONATOR IN QUANTITY SUFFICIENT TO PREVENT LARGE NON-AROMATIC ACCUMULATION IN THE SYSTEM.